1. September 19 th, 2011

2.  Average speed of a moving object is the total distance travelled divided by the total time elapsed  SI units for speed is meters per second (m/s) distance travelled (m) change in time (s)

3.  Your dog runs in a straight line for a distance of 43m in 28s. What is your dog’s average speed?  A baseball rolls along a flat parking lot in a straight line at a constant speed of 3.8 m/s. How far will the baseball roll in 15s?

4.  The average velocity of an object in motion is its total displacement, or change in position, divided by the total time taken for the motion, a.k.a. change in position over time

5.  If, what does the slope of a position time graph represent?

6.  On a windy day, the position of a balloon changes as it is blown 82m [N] away from a child in 15s. What is the average velocity of the balloon?  A subway train travels at an average velocity of 22.3 km/h [W]. How long will it take for the subway train to undergo a displacement of 241m [W]?

7.  Motion with uniform or constant velocity is motion at a constant speed in a straight line  Motion with non-uniform velocity is motion that is not at a constant speed or not in a straight line (can also be called accelerated motion)

8. ExampleUniform velocity? Non-uniform velocity? A car travels down a straight highway at a steady 100km/h A passenger on an amusement ride travels in a circle at a constant speed of 1.2m/s A car skids to a stop at a red light to avoid a crash

9. In pairs, describe the motion of an object whose position is modelled by the displayed graph

10.  In pairs, create a position time graph for your partner  Switch graphs, and describe a possible story that goes along with the graph!

11.  p. 20, #4-8

12.  Acceleration describes how quickly an object’s velocity changes over time, or the rate of change of velocity  What would a position time graph look like?

14.  To calculate velocity, we graphed position vs. time  To calculate acceleration, what should we graph?

15.  Calculate acceleration from the graph  Calculate displacement from the graph

16.  is the velocity of an object at a specific instant in time  is determined over a time interval  p. 28, sample problems #1 & 2